General Adaptation Syndrome Theory

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Practical Psychology

When was the last time you felt exhausted by stress? Anyone who has lived through 2020 can probably pinpoint a time where this occurred. Stress is exhausting! You and I already know that. But this exhaustion isn’t just a part of life. Chronic stress can pose serious risks to your life by way of your physical and mental health. Understanding stress can help you prevent stress, prevent exhaustion, and keep your body and mind healthy.

One way to take a look at the effects of stress on the body is to look at GAS. No, not that type of gas. In this video, we will take a look at General Adaptation Syndrome: what it is, what it says about stress in the body, and what it means for stress management and keeping track of your health.

What Is General Adaptation Syndrome?

Hans Selye was a Hungarian-Canadian endocrinologist who basically “discovered” stress. Historians believe that he first observed stress in people by realizing that they simply “looked sick,” rather than displaying common symptoms of illness. As he continued to observe animals and people put under pressure, he noticed that our physical bodies went through a similar process. This led to the creation of General Adaptation Syndrome.

General Adaptation Syndrome describes the physiological stages that the body goes through when it is exposed to stress. Although research on stress in the body has evolved since Hans Selye first “discovered” stress, the three stages of stress are still very relevant today.

Three Stages of GAS

The three stages of GAS are: alarm, resistance, and exhaustion. As we move through these three stages, we experience varying effects related to stress.


Alarm is the first stage of GAS. This occurs when we are first exposed to stress. In the early days of humankind, the alarm stage may have been triggered by seeing a saber-tooth tiger or encountering a warring tribe. Now, the alarm stage may go off by driving through traffic, getting fired from a job, or seeing a picture of your ex and their new partner on Instagram. Stress is everywhere!

The alarm stage isn’t just characterized by an emotional feeling. The two sub-stages of the alarm stage reveal just what happens in our body when we are exposed to stress.

The shock phase comes first. When we are shocked, our body temperature decreases and our blood pressure decreases. Hormones, including cortisol, epinephrine, and norepinephrine are released. The mind becomes more alert and focused and the body’s pain receptors and reproductive system are dialed down. All of these effects allow a person to respond to the stressor as if it were a saber-tooth tiger or something that could cause serious physical harm.

After the shock phase is the countershock phase. This is when the body enters what we call “fight or flight” mode. Stress hormones continue to be released, along with adrenaline. The body switches the “sympathetic nervous system” on. This doesn’t mean that we become more sympathetic to others - the sympathetic nervous system increases the heart rate and blood pressure. Fuel is released, and blood is directed away from the GI system to the heart. Again, these bodily responses give us the ability to fight or flee.


Once the stressor is removed, the sympathetic nervous system turns “off” and the parasympathetic nervous system turns “on.” We enter “rest and digest” mode, and the body starts to heal itself. When another stressor comes our way, we move back into the alarm stage.

As we know, stressful situations don’t just come and go so easily. We may find ourselves feeling stressed for an entire hour, day, week, or year. Situations like a busy job or a recent break-up keep us in that “fight or flight” mode, even though we are not in physical danger.

When this occurs, we enter into the resistance stage. If the body remains in “fight or flight” mode for a long period of time, it will try to resist and adapt to this “new normal.” Stress hormones continue to be released and blood pressure continues to remain high. As you can probably guess, this isn’t super great for the body. People are likely to lose concentration, become irritable, or experience symptoms of inflammation.


We can only resist stress for so long. If we remain in the resistance phase for a long period of time, we will enter the exhaustion stage. We also know this stage as going through “chronic stress.” This could take weeks or months. Many people may have experienced chronic stress during the pandemic but did not realize it. They might have just attributed their symptoms to other causes.

This exhaustion stage, outside of the GAS theory, may be known as burnout. 77% of people have experienced burnout at their jobs. The physical and mental symptoms of burnout or chronic stress can cause people to leave their job altogether!

The symptoms of chronic stress can be extensive. They include, but are not limited to:

  • Depressed mood
  • Anxiety
  • Trouble sleeping
  • Trouble concentrating
  • Fatigue
  • GI issues
  • Muscle tension
  • Aches and pains throughout the body
  • Decreased stress tolerance

In fact, between 60-80% of primary care visits involve one of these symptoms. Hans Selye wasn’t wrong when he said that stressed people simply looked sick. Stress really can make you sick! All of these symptoms can cause additional problems. Sleep, for example, is vital to our health and well-being. If stress is leaving you tossing and turning at night, you may lose sleep and prevent your body from going through all of the healing processes that come with sleep. Although many of us have entered the exhaustion phase throughout 2020, we must find ways to step out of it and live a healthier, less stressful life.

Stress Isn’t Bad, But It Must Be Managed

Nowadays, stress is viewed as something to be avoided. But Hans Selye is known for saying, “Man should not try to avoid stress any more than he would shun food, love or exercise.” Ironically, historians have reported that Selye would work 10- to 14-hour days, even on weekends. That sounds pretty stressful!

Selye wasn’t always right about his theories on stress in the body, but there is some truth into what he says about stress management. As the body experiences stress, it learns to adapt to stressors. If you can learn how to manage stress and step away from stress when it occurs, you will become more resilient and continue to avoid stress as it comes your way.

This idea is why, for example, many athletes take cold showers or use ice baths after practice. “Adapted cold showers” take information from Selye’s theory to form a routine that can help to relieve symptoms of depression and build resilience to stress. Stress is not all inherently bad. Managing stress appropriately can encourage our body to go through a healing process, ultimately making us stronger and more resilient people. But you have to know when and how to enter and exit the alarm stage of the General Adaptation Syndrome.

How to Manage Stress

The best way to prevent exhaustion and reap the “benefits” of life post-stress is to understand what is stressing you out and how you can calm yourself down. Remember, stress doesn’t just come in the form of a saber-tooth tiger or a physical danger. Looking at your bank account can stress you out. Scrolling through Instagram can stress you out. Reading the news can absolutely stress you out! Know what stresses you out, and know that it is okay to admit that simple things are stressful.

Once you understand what stresses you out, you must identify what doesn’t stress you out. What can you do to remove yourself from the three stages of GAS? For Hans Selye, he entered a daily routine that included a long bike ride and a morning dip in the pool. What can you do to “un-stress” you out? Go for a run? Watch a stand-up comedy special? Take your dog for a walk? Meditation, affirmations, or yoga?

Knowing how to remove yourself from stress isn’t just about living a happier life. You will live longer, with fewer health complications, if you can manage stress. You don’t have to eliminate it completely - one could argue that no one can eliminate stress entirely. But you can learn how to manage stress in a way that you do not avoid burnout or exhaustion.

Reference this article:

Practical Psychology. (2021, April). General Adaptation Syndrome Theory. Retrieved from

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